Specimen holder used for mounting

ABSTRACT

A novel specimen holder for specimen support devices for insertion in electron microscopes. The novel specimen holder of the invention provides mechanical support for specimen support devices and as well as electrical contacts to the specimens or specimen support devices.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is filed under the provisions of 35 U.S.C. §371 andclaims the priority of International Patent Application No.PCT/US2009/037396 filed on 17 Mar. 2009 entitled “Specimen Holder Usedfor Mounting Samples in Electron Microscopes” in the name of David P.Nackashi, et al., which claims priority of U.S. Provisional PatentApplication Nos. 61/037,115 filed on 17 Mar. 2008 and 61/085,650 filedon 1 Aug. 2008, all of which are hereby incorporated by reference hereinin their entirety.

FIELD

The invention relates generally to specimen holders used for mountingsamples in an electron microscope, e.g., a transmission electronmicroscope (TEM), a scanning transmission electron microscopy (STEM) andvariations of the scanning electron microscopes (SEM) that usetraditional TEM-type holders and stages.

BACKGROUND

The specimen holder is a component of an electron microscope providingthe physical support for specimens under observation. Specimen holderstraditionally used for TEMs and STEMs, as well as some modern SEMs,consist of a rod that is comprised of three key regions: the end, thebarrel and the specimen tip (see, e.g., FIG. 1). In addition tosupporting the specimen, the specimen holder provides an interfacebetween the inside of the instrument (i.e., a vacuum environment) andthe outside world.

To use the specimen holder, one or more samples are first placed on asupport device. The support device is then mechanically fixed in placeat the specimen tip, and the specimen holder is inserted into theelectron microscope through a load-lock. During insertion, the specimenholder is pushed into the electron microscope until it stops, whichresults in the specimen tip of the specimen holder being located in thecolumn of the microscope. At this point, the barrel of the specimenholder bridges the space between the inside of the microscope and theoutside of the load lock, and the end of the specimen holder is outsidethe microscope. To maintain an ultra-high vacuum environment inside theelectron microscope, flexible o-rings are typically found along thebarrel of the specimen holder, and these o-rings seal against themicroscope when the specimen holder is inserted. The exact shape andsize of the specimen holder varies with the type and manufacturer of theelectron microscope, but each holder contains these three key regions.

Interfacing semiconductor-based devices with specimen holders for use inelectron microscopes has seen limited commercial development. There are,however, a few applications that have either required an electricalinterface between the sample and the specimen holder, or haveincorporated semiconductor devices in a research environment.

Several electron microscopy techniques, including Electron Beam InducedCurrent (EBIC), require an electrical contact between a sample and thespecimen holder itself. Typically, this is done using a simple screw andmetallic clip, which is gently pressed down onto the sample bytightening the screw (see, X. Zhang and D. Joy, “A simple specimenholder for EBIC imaging on the Hitachi S800,” J. Microscopy Res. andTechn. , Vol. 26(2), pp. 182-183, 1993). A wire is either soldered tothe clip or looped around the screw head to provide an electrical pathfrom the sample, through the clip, and to the specimen holder whichroutes the wire outside of the instrument. This approach is tedious,requiring the user to manually align the clips over the appropriateregions on the device, then manually tighten every screw that is neededto complete an electrical path to the specimen holder. Because of thesmall size of these screws and the sample itself, this approach takestime and requires a substantial amount of dexterity.

An alternative approach (U.S. Pat. No. 5,124,645) requires a wirebond,or solder joint, to establish a more durable connection between thesample and the specimen tip of a specimen holder. These connections,however, are permanent and do not allow samples to be easilyinterchanged between experiments. Following an experiment, to exchangesamples, the specimen holder must be placed back into a wirebond machineor soldering must again be performed to create a new electricalconnection with the new sample. This approach is tedious, requires greatdexterity, and is likely to damage the specimen tip after repeated use.

An approach developed at the University of Illinois (U.S. patentapplication Ser. No. 11/192,300) addresses some of these concerns. Thisapproach allows a semiconductor device to be mounted in a specimen tip,making as many as twelve simultaneous electrical connections between theholder and the device. A frame (generally U-shaped) aligns the deviceand baseplate with electrical spring contact fingers and provides arigid surface against which the device is pressed, providing stabilityand forming electrical contacts between the device and the specimenholder. The baseplate is the component of the specimen tip that providesa stable surface upon which the device can be mounted, and containselectrical spring contact fingers in complementary positions to thedevice, which when aligned using the frame, make contacts simultaneouslybetween the baseplate and the device. Disadvantageously, spring contactfingers such as these are delicate and more difficult to manufacture.Removing the device from the baseplate completely exposes the springclips and presents an opportunity to accidentally bend or break thesefingers, compromising the electrical connections.

Considering the disadvantages of the prior art, a novel specimen holderis needed, wherein said specimen holder eliminates the need for delicatespring contact fingers and provides a simple method for repeatedlymounting and exchanging devices without disassembly or soldering.

SUMMARY

The present invention relates generally to a novel specimen holder whichprovides mechanical support for specimen support devices and as well aselectrical contacts to the specimens or specimen support devices.

In one aspect, an electron microscope specimen holder is described, saidspecimen holder comprising a body, a clipping means, and at least oneguide mechanism. The specimen holder may further comprise a spring or aspring cantilever.

In another aspect, an electron microscope specimen holder is described,said specimen holder comprising a body, a clipping means, and at leastone guide mechanism, wherein the clipping means comprise an article ofmanufacture having a top surface, a bottom surface, a first end, asecuring means, a second end, and at least one electrical contactintegrated on and/or in the bottom surface of the article. The securingmeans may comprise one of a pivot positioned between the first end andthe second end of the article; a fixed point at or near the first end ofthe article and wherein the article is flexible; or a set screw. Thespecimen holder may further comprise a spring or a spring cantilever.

In each of these aspects, the specimen holder may further comprise aspecimen support device mechanically secured between the clipping meansand the body. The specimen support device may comprise a frame, at leastone electrical lead and at least one membrane region.

In still another aspect, a method of providing an electrical contactbetween a specimen and a specimen holder of an electron microscope isdescribed, said method comprising:

positioning a specimen on a specimen support device, wherein thespecimen support device comprises a frame, at least one electrical leadand at least one membrane region; and

inserting the specimen support device in a specimen holder, wherein thespecimen holder comprises a body, a clipping means, and at least oneguide mechanism, wherein the clipping means comprise at least oneelectrical contact integrated on and/or in a bottom surface of theclipping means; and wherein at least one electrical lead of the devicesubstantially contacts at least one electrical contact of the clippingmeans.

Yet another aspect relates to a method of using a specimen holder inelectron microscopy, said method comprising:

positioning a specimen support device in a specimen holder as describedherein; and

inserting said specimen holder in an electron microscope.

Other aspects, features and advantages of the invention will be morefully apparent from the ensuing disclosure and appended claims.

BRIEF DESCRIPTION OF FIGURES

FIG. 1 shows a schematic of a generic specimen holder (50). The specimenholder is comprised of three regions: the tip (100), the barrel (200),and the end (300).

FIG. 2A shows one embodiment of the tip region of a specimen holderdescribed herein wherein the holder tip (10000) shows a clampingmechanism in an open state ready to receive a specimen support device.

FIG. 2B shows one embodiment of the tip region of a specimen holderdescribed herein wherein the holder tip (10000) shows a clampingmechanism in a closed state without a specimen support device.

FIG. 2C shows one embodiment of the tip region of a specimen holderdescribed herein wherein the holder tip (10000) shows a clampingmechanism in a closed state with a specimen support device.

FIG. 3A shows a second embodiment of the tip region of a specimen holderdescribed herein wherein the holder tip (30000) shows a clampingmechanism in an open state ready to receive a specimen support device.

FIG. 3B shows a second embodiment of the tip region of a specimen holderdescribed herein wherein the holder tip (30000) shows a clampingmechanism in a closed state without a specimen support device.

FIG. 3C shows a second embodiment of the tip region of a specimen holderdescribed herein wherein the holder tip (30000) shows a clampingmechanism in an closed state with a specimen support device.

FIG. 4A shows a third embodiment of the tip region of a specimen holderdescribed herein wherein the holder tip (50000) shows a flexingmechanism ready to receive a specimen support device, wherein thefulcrum is a two-piece fulcrum.

FIG. 4B shows a third embodiment of the tip region of a specimen holderdescribed herein wherein the holder tip (50000) shows a flexingmechanism with a specimen support device, wherein the fulcrum is atwo-piece fulcrum.

FIG. 5A shows a fourth embodiment of the tip region of a specimen holderdescribed herein wherein the holder tip (50000) shows a flexingmechanism ready to receive a specimen support device, wherein thefulcrum is a one-piece fulcrum.

FIG. 5B shows a fourth embodiment of the tip region of a specimen holderdescribed herein wherein the holder tip (50000) shows a flexingmechanism with a specimen support device, wherein the fulcrum is aone-piece fulcrum.

FIG. 6A shows a fifth embodiment of the tip region of a specimen holderdescribed herein wherein the holder tip (60000) shows a clampingmechanism in an open state ready to receive a specimen support device.

FIG. 6B shows a fifth embodiment of the tip region of a specimen holderdescribed herein wherein the holder tip (60000) shows a clampingmechanism in a closed state without a specimen support device.

FIG. 6C shows a fifth embodiment of the tip region of a specimen holderdescribed herein wherein the holder tip (60000) shows a clampingmechanism in a closed state with a specimen support device.

FIG. 7 shows an sixth embodiment of the tip region of a specimen holderdescribed herein, wherein the holder tip (60000) shows a clampingmechanism in a closed state with a specimen support device.

FIG. 8 shows an seventh embodiment of the tip region of a specimenholder described herein, wherein the holder tip (60000) shows a clampingmechanism in a closed state with a specimen support device.

DETAILED DESCRIPTION

The present invention generally relates to novel specimen holders,methods for interfacing samples at the tip of the specimen holder, anduses of the novel specimen holder. It is to be understood that thespecimen holder and specimen holder interface described herein arecompatible with and may be interfaced with the semiconductor specimensupport devices disclosed in U.S. Patent Application Nos. 60/916,916 and60/974,384, which are incorporated herein by reference in theirentirities. It should be appreciated by one skilled in the art thatalternative specimen support devices may be interfaced with the specimenholder described herein. The specimen holder provides mechanical supportfor one or more specimens or specimen support devices and may alsoprovide electrical contacts to the specimens or specimen supportdevices. The specimen holder can be manufactured with tips, barrels andends of various shapes and sizes such that the specimen holder fits anymanufacturer's electron microscope.

As defined herein, a “spring” corresponds to any object that has aspring constant (k) and which exerts a force onto the specimen supportdevice when it is loaded in the specimen holder. The spring may or maynot observe Hooke's law (F=−kx) depending on the material ofconstruction.

As defined herein, a “hinge” connects two solid objects, in the presentcase the insulating clip and the mounting surface, typically allowingonly a limited angle of rotation between them. Two objects connected bya hinge rotate relative to each other about a fixed axis of rotation. Itis also contemplated herein that the “hinge” may be one or two fulcrumsattached to the mounting surface, wherein the clip is flexible.

As defined herein, a “membrane region” corresponds to unsupportedmaterial comprised, consisting of, or consisting essentially of carbon,silicon nitride, SiC or other thin films generally 1 micron or lesshaving a low tensile stress (<500 MPa), and providing a region at leastpartially electron transparent region for supporting the at least onespecimen. The membrane region may include holes or be hole-free. Themembrane region may be comprised of a single material or a layer of morethan one material and may be either uniformly flat or contain regionswith varying thicknesses.

The present application improves on the prior art in several ways: (1)by eliminating the required use of a delicate spring contact finger, (2)by providing a method for accommodating semiconductor devices that areof various shapes and sizes without the need to machine frames andcustom parts to align different devices geometries, and (3) by providinga simple method for mounting and exchanging devices and makingelectrical contacts to devices without the need for partiallydisassembling the specimen tip (e.g., removing screws or other smallparts).

More specifically, rather than using spring contact fingers (bentslightly at their tips) to separately promote contact with each pad onthe device, the specimen holder described herein includes at least oneelectrode placed on the bottom of an insulating clip, wherein theinsulating clip with integrated electrode(s) provides simultaneousmechanical force to all electrodes, simultaneously presses theelectrode(s) against contact pads on the device and provides mechanicalforce for securing the device in place for imaging. Clips and springsused in this application separately provide the mechanical forcerequired to stabilize the device to the specimen holder, and are notused for electrical contacts between the device and the holder.Preferably, the springs are distally positioned along the insulatingclip relative to the electrical contacts. This allows the electricalcontacts on the clips to be manufactured using planar processes such as,but not limited to, precision machining, lithographic and/orelectroplating processes.

Using the specimen holder described herein, only one side of the deviceis required to have contact pads matching the electrode pitch and widthin order to line up with the electrodes underneath the clip. This designimproves upon prior art in that it allows a variety of device lengthsand shapes to be mounted into the specimen tip. This specimen holderalso allows a device to be mounted quickly and easily, making bothphysical and electrical contacts, without the need to partiallydisassemble the specimen tip to mount the device.

One embodiment of the tip region of a specimen holder is shown is FIGS.2A, 2B and 2C. FIG. 2A shows the tip region of a specimen holder whereinthe holder tip (10000) includes a clamping mechanism in an open stateready to receive a specimen support device. FIG. 2B shows the tip regionof the specimen holder of FIG. 2A wherein the holder tip (10000) is in aclosed state without a specimen support device. FIG. 2C shows the tipregion of the specimen holder of FIG. 2A wherein the holder tip (10000)is in an closed state with a specimen support device. In each of thesefigures, the clamping mechanism is comprised of a clip (10100), spring(10200), hinges (10300), set screw (10400), guide mechanism (10500),depth stop (10600), and at least one electrical contact (10700). Theholder tip is comprised of a body (10025), a viewing region (10050), andthe clamping mechanism. In FIG. 2C a device is loaded into the tip andheld in place by the clamping mechanism. The device is generallycomprised of a frame (20000), electrical leads (20100), and a membraneregion (20200).

In the clamping mechanism, the clip (10100) acts as a lever, the spring(10200) provides constant tension to the clip, the hinges (10300) allowthe clip to pivot about the hinge, the set screw (10400) prevents thespring (10200) from being over-compressed when a device is loaded, andthe guide mechanism (10500), such as guide screws, guide pins, or guideposts, provides lateral alignment to a device as it is loaded. When adevice is completely loaded, the depth stop (10600) provides a meansboth to align the electrical contacts of the specimen holder (10700) toelectrical leads of a device (20100) and to align the viewing region ofthe specimen holder tip (10050) with the membrane region of a device(20200). It should be appreciated by one skilled in the art that theelectrical contacts of the specimen holder (10700) may extend from onelength of the clip to the other or may be present in shorter sections solong as the electrical contacts are present for contact with theelectrical leads of the device (20100).

The resting position for the clamping mechanism is shown in FIG. 2Bwhere a spring (10200) pushes upward at one end of the clip (10100),resulting in downward pressure created at the opposite end of the clipwhere the clip pivots at a set of hinges (10300). The hinge is mountedto a planar mounting surface (10800), said mounting surface extendingfrom the barrel to at least the end of the clip and possibly further.When this mounting surface extends beyond the clip, a viewing region(10050) will typically be included therein just beyond the clip.

To mount the device, downward pressure is placed on the spring end ofthe clip, which lifts the opposite end above the surface to a level atleast as high as the thickness of the device, and typically higher, forexample, greater than 1 mm (see FIG. 2A), although less than 1 mm iscontemplated. The device is either placed in between the clip and themounting surface manually, or slid underneath the clip along themounting surface using the guide screws and depth stop as guidance. Oncethe device is in position, the pressure on the spring is released andthe device is secured manually to the specimen tip (see FIG. 2C).

Electrical contacts from the holder to the device, typically in a rangefrom 2 to 12 electrical contacts (10700), may be provided by theintegrated conducting wires or paths underneath the clip. Theseelectrical contacts are electrically isolated from each other and fromthe clip itself (if the clip is made of a conductive material). Whenelectrical pads exist on the device, the guide mechanism and depth stopwill align the device with the clip to allow the electrical contactsfrom the clip and the pads from the device to contact one another whendownward pressure on the clip is released. This will allow bothmechanical pressure and electrical connections to be made in a novel,easy to operate design. The electrical contacts will extend from theclip to the barrel, down the barrel to the end, and to a connector thatexists at the specimen holder end that can be mated with a plug outsidethe microscope and connected to a power supply to provide voltage orcurrent through the holder and interface to the specimen support device.Each conductor will remain isolated from each other as well as the threecomponents of the specimen holder.

Another embodiment of the tip region of a specimen holder is shown inFIGS. 3A, 3B, and 3C. FIG. 3A shows the tip region of a specimen holderof the present invention where the holder tip (30000) includes aclamping mechanism in an open state ready to receive a specimen supportdevice. FIG. 3B shows the tip region of the specimen holder of FIG. 3Awhere the holder tip (30000) is in a closed state without a specimensupport device. FIG. 3C shows the tip region of the specimen holder ofFIG. 3A where the holder tip (30000) is in a closed state with aspecimen support device. In each of these figures, the clampingmechanism is comprised of a clip (30100), spring (30200), locking screw(30300), guide mechanism (30400), depth stop (30500), and at least oneelectrical contact (30600). The holder tip is comprised of a body(30025), a viewing region (30050), and the clamping mechanism. In FIG.3C a device is loaded into the tip and held in place by the clampingmechanism. The device is generally comprised of a frame (20000),electrical leads (20100), and a membrane region (20200).

In the clamping mechanism, the clip (30100) acts as a clamp, the spring(30200) provides constant tension to the clip, the locking screw (30300)allows the clip to move up and down parallel to the plane of the body(30025), the guide mechanism (30400), such as guide screws, guide pins,or guide posts, provide lateral alignment to a device as it is loaded.When a device is completely loaded, the depth stop (30500) provides ameans both to align the electrical contacts of the specimen holder(30600) to electrical leads of a device (20100) and to align the viewingregion of the specimen holder tip (30050) with the membrane region of adevice (20200). It should be appreciated by one skilled in the art thatthe electrical contacts of the specimen holder (30600) may extend fromone length of the clip to the other or may be present in shortersections so long as the electrical contacts are present for contact withthe electrical leads of the device (20100).

The open position for the clamping mechanism is shown in FIG. 3B where aspring (30200) pushes upward at one end of the clip (30100), resultingin downward pressure pushing at the opposite end of the clip. The clipcan be raised or lowered by a locking screw (30300) and when raised, theforce exerted by the spring is enough to ensure that the front of theclip is raised enough to allow a specimen support device to be loadedinto the holder.

To mount the device, the locking screw is turned to raise the clip to alevel at least as high as the thickness of the device, and typicallyhigher, e.g., greater than 1 mm (see FIG. 3A), although less than 1 mmis contemplated. The device is either placed in between the clip and thesurface manually, or slid underneath the clip along the surface usingthe guide screws and depth stop as guidance. Once the device is inposition, the locking screw is turned to lower the clip so that the clipsecures the device to the specimen tip (see FIG. 3C).

Electrical contacts from the holder to the device, typically in a rangefrom 2 to 12 electrical contacts (30600), may be provided by theintegrated conducting wires or paths underneath the clip. Theseelectrical contacts are electrically isolated from each other and fromthe clip itself (if the clip is made of a conductive material). Whenelectrical pads exist on the device, the guide screws and depth stopwill align the device with the clip to allow the electrical contactsfrom the clip and the pads from the device to contact one another whendownward pressure on the clip is released. This will allow bothmechanical pressure and electrical connections to be made in a novel,easy to operate design. The electrical contacts will extend from theclip to the barrel, down the barrel to the end, and to a connector thatexists at the specimen holder end that can be mated with a plug outsidethe microscope and connected to a power supply. Each conductor willremain isolated from each other as well as the three components of thespecimen holder.

Yet another embodiment of the tip region of a specimen holder is shownin FIGS. 4A, 4B and 5A, 5B. FIGS. 4B and 5B show the tip region of aspecimen holder of the present invention where the holder tip (50000)includes a flexible clamping mechanism in the resting state with aspecimen support device loaded for use. FIGS. 4A and 5A show the tipregion of the specimen holder of FIGS. 4B and 5B, respectively, wherethe holder tip (50000) is in a state ready for unloading a specimensupport device. In all of these figures the flexible mechanism iscomprised of a clip (50100) under which the device can be inserted,guide mechanism (50400), depth stop (50500), fulcrum (50600), fixedpoint (50300) and at least one electrical contact (50700). An optionalset screw (50200) can be used to limit the distance that the clip can beflexed. The holder tip is comprised of a body (50025), a viewing region(50050) and a flexible clamping mechanism. The device is comprised of aframe (20000), electrical leads (20100), and a membrane region (20200).The difference between the 4A, 4B figures and the 5A, 5B figures is thatin the former the fulcrum is a two-piece fulcrum and in the in latterthe fulcrum is a one-piece fulcrum.

To mount the device under the clip (50100), the device is first orientedbetween the guide screws (50400) with the device's electrical leads(20100) oriented towards the slot. Downward pressure is then applied onthe top surface of the clip (50100) at a point between the fulcrum(50600) and the fixed point (50300) resulting in the clip (50100)bending upward at the end near the guide mechanism (50400), such asguide screws, guide pins, or guide posts. With this pressure applied,the device is then inserted until the leading edge of the device meetsthe depth stop (50500). When the device is fully inserted against thedepth stop (50500), the downward force on the clip (50100) is releasedwhich secures the device under the clip (50100) by friction duringimaging and analysis. Simultaneous electrical contacts are formedbetween the electrical contacts (50700) underneath the clip (50100) andthe electrical leads (20100) allowing electrical current to be passedfrom the electrical contacts (50700) to the electrical leads (20100). Itshould be appreciated by one skilled in the art that the electricalcontacts of the specimen holder (50700) may extend from one length ofthe clip to the other or may be present in shorter sections so long asthe electrical contacts are present for contact with the electricalleads of the device (20100).

Another embodiment of the tip region of a specimen holder is shown inFIGS. 6A, 6B, and 6C. FIG. 6A shows the tip region of a specimen holderof the present invention where the holder tip (60000) includes aclamping mechanism in an open state ready to receive a specimen supportdevice. FIG. 6B shows the tip region of the specimen holder of FIG. 6Awhere the holder tip (60000) is in a closed state without a specimensupport device. FIG. 6C shows the tip region of the specimen holder ofFIG. 6A where the holder tip (60000) is in a closed state with aspecimen support device. In each of these figures, the clampingmechanism is comprised of a clip (60100), spring cantilever (60200),post (60800), post hole (60400), pivots (60300), guide mechanism(60500), depth stop (60600), and at least one electrical contact(60700). The post hole (60400) allows the post (60800) to contact and/orconnect to both the spring cantilever (60200) and the clip (60100)through the holder tip (60000). The holder tip is comprised of a body(60025), a viewing region (60050), and the clamping mechanism. Theelectrical contact(s) preferably do not flex like a spring and will notbe damaged from fatigue. In FIG. 6C a device is loaded into the tip andheld in place by the clamping mechanism. The device is generallycomprised of a frame (20000), electrical leads (20100), and a membraneregion (20200).

In the clamping mechanism, the clip (60100) acts as a lever, the springcantilever (60200) and post (60800) provide constant tension to theclip, the pivot (60300) allow the clip to pivot, and the guide mechanism(60500), such as guide screws, guide pins, or guide posts, provideslateral alignment to a device as it is loaded. When a device iscompletely loaded, the depth stop (60600) provides a means both to alignthe electrical contacts of the specimen holder (60700) to electricalleads of a device (20100) and to align the viewing region of thespecimen holder tip (60050) with the membrane region of a device(20200). It should be appreciated by one skilled in the art that theelectrical contacts of the specimen holder (60700) may extend from onelength of the clip to the other or may be present in shorter sections solong as the electrical contacts are present for contact with theelectrical leads of the device (20100). In addition the electricalcontacts (60700) may consist of wires that protrude from the end of theclip, which make electrical contact to the electrical leads of thedevice (20100) using the bottom surface of the wire, or alternatively donot protrude from the end of the clip (see, e.g., FIG. 8 whichillustrates the electrical contacts stopping at (or before) the end ofthe clip (60100).

The resting position for the clamping mechanism is shown in FIG. 6Bwhere a spring cantilever (60200) pushes upward on a post (60800)through a post hole (60400), which pushes upward at one end of the clip(60100), resulting in downward pressure created at the opposite end ofthe clip where the clip pivots at a set of pivots (60300) which may besmooth or threaded. The pivot is mounted to a mounting surface that ispart of the body holder tip (60200).

To mount the device, downward pressure is placed on the spring end ofthe clip, which lifts the opposite end above the surface to a level atleast as high as the thickness of the device, and typically higher, forexample, greater than 1 mm (see FIG. 6A), although less than 1 mm iscontemplated. The device is either placed in between the clip and themounting surface manually, or slid underneath the clip along themounting surface using the guide mechanism and depth stop as guidance.Once the device is in position, the pressure on the spring is releasedand the device is secured manually to the specimen tip (see FIG. 6C).

Electrical contacts from the holder to the device, typically in a rangefrom 2 to 12 electrical contacts (60700 and 20100), may be provided bythe conducting wires or paths and these electrical contacts may bepositioned above, within, underneath and/or extended from the clip.These electrical contacts are electrically isolated from each other andfrom the clip itself (if the clip is made of a conductive material).When electrical pads exist on the device, the guide mechanism and depthstop will align the device with the clip to allow the electricalcontacts from the clip and the pads from the device to contact oneanother when downward pressure on the clip is released. This will allowboth mechanical pressure and electrical connections to be made in anovel, easy to operate design. The electrical contacts will be routedfrom the clip to the barrel, down the barrel to the end, and to aconnector that exists at the specimen holder end that can be mated witha plug outside the microscope and connected to a power supply to providevoltage or current through the holder and interface to the specimensupport device. Each conductor can remain isolated from each other aswell as the three components that comprise the specimen holder.

Further embodiments of the tip region of the specimen holder are shownin FIGS. 7 and 8. FIG. 7 shows the tip region of a specimen holdersimilar to FIG. 6C, wherein the holder tip (60000) is in a closed statewith a specimen support device, however, the mounting surface of theholder tip only extends about as far as the electrical contacts (60700)and as such, the holder tip does not include the viewing region of FIG.6C. FIG. 8 also shows the tip region of a specimen holder similar toFIG. 6C, however, the electrical contacts do not extend beyond the endof the clip. Specifically, in FIGS. 7 and 8, the clamping mechanism iscomprised of a clip (60100), spring cantilever (60200), post (60800),post hole (60400), pivots (60300), depth stop (60600), and at least oneelectrical contact (60700). The post hole (60400) allows the post(60800) to contact and/or connect to both the spring cantilever (60200)and the clip (60100) through the holder tip (60000). The electricalcontact(s) preferably do not flex like a spring and will not be damagedfrom fatigue. The holder tip is comprised of a body (60025) and theclamping mechanism. In FIG. 7, the body (60025) extends just to the edgeof the electrical contacts (60700) and the specimen support device(20000) cantilevers beyond the body (60025). In FIG. 8, the electricalcontacts (60700) do not extend beyond the end of the clip (60100) andthe body (60025) is illustrated to extend as far as the edge of the clip(60100), wherein the specimen support device (20000) cantilevers beyondthe body (60025). The embodiments in FIGS. 7 and 8 allow a rigidspecimen support to extend beyond the body (60025) and still maintainmechanical contact with the body (60025) and electrical contact with theclip (60100) through the electrical contacts (60700).

FIG. 7 and FIG. 8 are based upon the embodiment illustrated in FIGS. 6A,6B and 6C, but may also be applied to the embodiments shown in FIGS. 2A,2B, 2C, 3A, 3B, 3C, 4A, 4B, 5A and 5B, whereby the mounting surface ofthe holder tip only extends about as far as the electrical contacts andas such, the holder tip does not include the viewing region.

The advantages of the specimen holder described herein include, but arenot limited to: the ready adaptation of the specimen holder toaccommodate specimen support devices having varying shapes and sizeswithout the need to machine frames and custom parts to align differentdevice geometries; providing a simple method for mounting and exchangingdevices and making electrical contacts to devices without the need forpartially disassembling the specimen tip; allowing for interchangeablespecimen tips to accommodate different specimen supports or to be usedwith different barrels and ends; and eliminating the use of a delicatespring contact finger. For example, the electrical contacts of thepresent invention may be effectuated at one of the clip (see, e.g.,FIGS. 2-8) whereby there is no spring present at all or the spring isdistally positioned at the other end of the clip.

Although the invention has been variously disclosed herein withreference to illustrative embodiments and features, it will beappreciated that the embodiments and features described hereinabove arenot intended to limit the invention, and that other variations,modifications and other embodiments will suggest themselves to those ofordinary skill in the art, based on the disclosure herein. The inventiontherefore is to be broadly construed, as encompassing all suchvariations, modifications and alternative embodiments within the spiritand scope of the claims hereafter set forth.

What is claimed is:
 1. An electron microscope specimen holder comprisinga body, a clipping means, and at least one guide mechanism, wherein theclipping means comprise an article of manufacture having a top surface,a bottom surface, a first end, a securing means, a second end, and atleast one electrical contact integrated on and/or in the bottom surfaceof the article, wherein the specimen holder further comprises a springcantilever and a means of contacting said spring cantilever with thebottom surface of the first end of the article, wherein the springcantilever provides constant tension to the first end of the article. 2.The specimen holder of claim 1, wherein the securing means comprise apivot positioned between the first end and the second end of thearticle.
 3. The specimen holder of claim 1, wherein the second end ofthe article is pivotally raised by applying downward pressure to the topsurface of the first end of the article for insertion of a specimensupport device between the bottom surface of the second end of thearticle and a top surface of the body.
 4. The specimen holder of claim1, wherein the article is pivotally lowered such that at least oneelectrical lead of a specimen support device substantially contacts atleast one electrical contact of the article.
 5. The specimen holder ofclaim 1, wherein the at least one electrical contact extends from thesecond end of the article, terminates at the second end of the article,or terminates before the second end of the article.
 6. The specimenholder of claim 1, wherein the at least one electrical contact of theclip extends from the clip to a barrel, from the barrel to an end, andonto an electrical connector.
 7. The specimen holder of claim 1, furthercomprising a specimen support device mechanically secured between theclipping means and the body.
 8. A method of using a specimen holder inelectron microscopy, said method comprising: positioning a specimensupport device in the specimen holder of claim 1; and inserting saidspecimen holder in an electron microscope.
 9. The method of claim 8,wherein a specimen is on the specimen support device and an electronbeam is controlled to form an image of the specimen.
 10. The specimenholder of claim 1, wherein the means of contacting said springcantilever with the bottom surface of the first end of the articlecomprise a post.
 11. The specimen holder of claim 1, wherein thespecimen holder comprises a viewing region.
 12. The specimen holder ofclaim 1, wherein the guide mechanism is selected from the groupconsisting of guide screws, guide pins, and guide posts.
 13. Thespecimen holder of claim 1, wherein the specimen holder furthercomprises a depth stop to align the at least one electrical contact ofthe specimen holder with at least one electrical lead of a specimensupport device.
 14. The specimen holder of claim 13, wherein the depthstop further aligns a viewing region of the specimen holder with amembrane region of the specimen support device.
 15. The specimen holderof claim 1, comprising 2 to 12 electrical contacts.
 16. The specimenholder of claim 15, wherein the electrical contacts are electricallyisolated from one another.
 17. A method of providing an electricalcontact between a specimen and a specimen holder of an electronmicroscope, said method comprising: positioning a specimen on a specimensupport device, wherein the specimen support device comprises a frame,at least one electrical lead and at least one membrane region; andinserting the specimen support device in a specimen holder, wherein thespecimen holder comprises a body, a clipping means, and at least oneguide mechanism, wherein the clipping means comprise an article ofmanufacture having a top surface, a bottom surface, a first end, asecuring means, a second end, and at least one electrical contactintegrated on and/or in a bottom surface of the article, wherein thespecimen holder further comprises a spring cantilever and a means ofcontacting said spring cantilever with the bottom surface of the firstend of the article, wherein the spring cantilever provides constanttension to the first end of the article; and wherein at least oneelectrical lead of the device substantially contacts at least oneelectrical contact of the clipping means.
 18. The specimen holder ofclaim 1, wherein the guide mechanism provides lateral alignment to adevice as it is loaded.